Changeset 104804 in vbox for trunk/src/VBox/Devices/USB

Timestamp:

May 28, 2024 1:04:36 PM (9 months ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

163376

Message:

Devices/USB: Fix a deadlock in OHCI triggered when saving the current
state of a VM or taking a snapshot. bugref:10692 ticketref:22059

Location:

trunk/src/VBox/Devices/USB

Files:

• DrvVUSBRootHub.cpp (modified) (5 diffs)
• VUSBInternal.h (modified) (1 diff)

trunk/src/VBox/Devices/USB/DrvVUSBRootHub.cpp

@@ -711 +711 @@
 
     /* Don't do anything if we are not supposed to process anything (EHCI and XHCI). */
-    if (!pThis->uFrameRateDefault)
+    if (   !pThis->uFrameRateDefault
+        || ASMAtomicReadBool(&pThis->fSavingState))
         return 0;
 
@@ -1374 +1375 @@
     RT_NOREF(pSSM);
 
+    ASMAtomicXchgBool(&pThis->fSavingState, true);
+
     /*
      * If there is old load state hanging around, we'll have to execute it first
@@ -1391 +1394 @@
      * Detach all proxied devices.
      */
-    RTCritSectEnter(&pThis->CritSectDevices);
 
     /** @todo we a) can't tell which are proxied, and b) this won't work well when continuing after saving! */
     for (unsigned i = 0; i < RT_ELEMENTS(pThis->apDevByPort); i++)
     {
-        PVUSBDEV pDev = pThis->apDevByPort[i];
+        PVUSBDEV pDev = vusbR3RhGetVUsbDevByPortRetain(pThis, i, "SavePrep");
         if (pDev)
         {
@@ -1409 +1411 @@
                  * called unconditionally if the Prep handler was called.
                  */
+                Assert(!pThis->apDevByPort[i]);
                 pThis->apDevByPort[i] = pDev;
+                vusbDevRelease(pDev, "SavePrep");
             }
         }
     }
-
-    RTCritSectLeave(&pThis->CritSectDevices);
 
     return VINF_SUCCESS;
@@ -1452 +1454 @@
     }
 
+    ASMAtomicXchgBool(&pThis->fSavingState, false);
     return VINF_SUCCESS;
 }

trunk/src/VBox/Devices/USB/VUSBInternal.h

@@ -422 +422 @@
     /** Flag whether a frame is currently being processed. */
     volatile bool              fFrameProcessing;
+    /** Flag whether we are in the middle of saving the VM state. */
+    volatile bool              fSavingState;
 
 #if HC_ARCH_BITS == 32